Application of fracture mechanics to heterogeneous systems — prediction of fatigue life of ceramics

A prediction of fatigue life and fracture stress of ceramics of a heterogeneous system was made by application of fracture mechanics based on slow crack growth. It was shown that the prediction of fatigue life and fracture stress in ceramics of heterogeneous system in general could be dealt with in a similar way to those of ceramics of a homogeneous system. Experimental examination of the validity of the prediction was made with LAS glass ceramics (Li₂O-Al₂O₃-SiO₂) at various stages of devitrification as well as foamed glass. These results proved the validity of the formulae derived.     

Thermal stress in a bimodulus thick cylinder

Certain materials are known to behave differently under tension and compression. This reports an investigation of a simple thermal stress problem based on the bimodulus elasticity in the framework of the classical-type uncoupled thermoelasticity. Because of an unavoidable complexity of three-dimensional analysis in bimodulus elasticity, as a fundamental illustration we consider herein an axisymmetric plane strain state of a thick orthotropic circular cylinder under axisymmetric heat conditions. A system of transcendental simultaneous algebraic equations with respect to eight unknowns are derived. Numerical analyses are carried out for a steady-state temperature field and for a quasi-stationary state with internal heat generation. Results of calculations show that the states of a cylinder are affected significantly by the difference between tensile and compressive moduli of elasticity.     

Analysis of air pollution and prevalence rate of allergic diseases among elementary school children in Kawaguchi and Hatogaya city

Kawaguchi and Hatogaya City are located on the northern edge of Tokyo. We analysed between air pollution and prevalence rate of allergic diseases among elementary school children in this area. A prevalence rate of allergic diseases in 1996 May and June was as follows; bronchial asthma 13.5%, atopic dermatitis 24.5%, allergic rhinitis and/or conjunctivitis 22.8%, urticaria 12.4%, food allergy 7.8% and drug allergy 2.2%, respectively. Air pollution of this area was analysed to check the levels of nitrogen dioxide (NO2), sulfur dioxide (SO2) and suspended particulate matters (SPM). NO2 pollution was relatively high in urban area, and SPM pollution was especially high around the highways. SO2 pollution was lower than the environmental standard. No relationship was found between the prevalence rate of bronchial asthma, atopic dermatitis, allergic rhinitis and/or conjunctivitis and air pollution, but it was found that these diseases are slightly related to population density (p < 0.1, p < 0.01, p < 0.1, respectively).     

Effective treatment of mice with type II collagen induced arthritis with lethal irradiation and bone marrow transplantation

Ricin A-chain is delivered into macrophages via receptor-mediated endocytosis. We have found that following uptake via the mannose receptor, ricin A-chain is rapidly cleaved by endosomal proteases. Inhibition of endosomal proteases such as cathepsin D and B leads to the accumulation of toxin inside the cell. Inhibition of cathepsin D reduces ricin A-chain cytotoxicity, while blocking cathepsin B enhances cytotoxicity. Similar results were obtained using fibroblasts transfected with the mannose receptor. Our data strongly suggest that the activation or membrane translocation of ricin A-chain is dependent upon the action of specific proteases.     

The development of a diagnostic and monitoring system for vibrating pipe branches

This paper deals with a diagnostic and monitoring system for assessing the integrity of pipe branches, during the operation of the nuclear power plant. This system have been developed under the concept of “easy to use without any sophisticated analysis” and “portable”. The accuracy of the diagnosis is based on the model optimization subsystem, which automatically modifies the numerical vibration model so as to fit its natural frequency to the actual natural frequency. The information obtained by this system may be reflected to a maintenance program of the plant to assure more reliable operation of the plant.     

Abdominal aortic aneurysm repair with arterial branch reconstruction: utility of the temporary bypass technique

A 6-year prospective study of 80 abdominoplasties is reported. Type and incidence of complications are presented with particular attention toward the incidence of fluid collection following abdominoplasty, such as seroma and hematoma. Ultrasound was performed in 56 patients (70%), with normal findings in 27 patients (48%). Accurate diagnosis of fluid collection in 29 patients (51.8%), seroma in 24 (42.8%), and hematoma in 5 (9%) was confirmed with the aid of ultrasound. The advantage of early radiological diagnosis alerted the surgeon for positive findings of fluid collection areas in the abdominal wall, which resulted in close observation and early intervention whenever indicated. Ultrasound of the abdominal wall following abdominoplasty provides a noninvasive, accurate, and low-cost method of diagnosing fluid collection in the abdominal wall. This method, if performed routinely postabdominoplasty, will aid the surgeon in managing potential complications such as wound-healing problems, infection, and patient discomfort.